Prevalence and associated factors of metabolic syndrome among pregnant Ethiopian women: a hospital-based cross-sectional study

Metabolic syndrome (MetS) poses a significant public health challenge globally, including in Ethiopia, with risks for both mothers and children. Unfortunately, there is limited data on MetS in pregnant Ethiopian women. This study aims to evaluate the prevalence and factors associated with MetS in this population. A cross-sectional study was conducted using a systematic random sampling technique. Data were collected through face-to-face interviews using a structured questionnaire adapted from the World Health Organization Steps Survey Tool for Non-communicable Diseases. About five ml of fasting peripheral blood samples were collected from each participant. The Beckman Coulter DXC 700 AU clinical chemistry analyzer was employed for lipid profile and glucose analysis. Subsequently, data were inputted into Epi Data and later exported to SPSS Version 20 for further analysis. Bivariable and multivariable binary logistic regression analyses were carried out, with a predefined level of statistical significance at p < 0.05. A total of 318 pregnant women were included in this study. The prevalence of MetS was 13.2% (95% CI: 9.7, 17.0) based on the American Heart Association/National Heart Lung and Blood Institute definition. The most prevalent components of MetS were elevated triglyceride levels, reduced high-density lipoprotein levels, and elevated blood pressure. Unhealthy sleep duration (AOR = 5.6, 95% CI (2.4, 13.1), p < 0.001), high daily salt intake (AOR = 4.2, 95% CI (1.8, 9.5), p = 0.001), and alcohol consumption [AOR = 4.2, 95% CI (1.6, 10.9), p = 0.003] were significantly associated with MetS. The study reported a high prevalence of MetS in pregnant Ethiopian women. Factors including alcohol, high salt intake, and sleep disturbances were associated with MetS. Policymakers might utilize this data to create targeted interventions and public health policies for MetS among pregnant women, focusing on nutrition, sleep, and alcohol consumption during pregnancy to safeguard maternal and fetal health.


Sample size and sampling methods
The sample size for this study was calculated using the single population proportion formula: Z2 = p (1 − p) d2).Since the prevalence of MetS in Ethiopian pregnant women is unknown, the p-value was obtained from a study conducted on pregnant women in Angola (29.2%) 12 with a confidence level of 95% and a marginal error (d) of 5%.In total, 318 pregnant women were included in this study, and the selection of participants was carried out through a systematic random sampling technique.

Study participants
All pregnant women over 18 years old in their first to third trimesters were included in the study.Pregnant women who were severely ill, with known diabetes and hypertension (HTN) were excluded.Pregnant mothers who were in 2nd, and 3rd trimester, but came for their first visit or with reference were excluded because of the unavailability of pre-pregnancy weight, which was used to calculate the pre-pregnancy BMI.Additionally, pregnant women who were infected with HIV and seropositive for hepatitis B and C were also excluded by reviewing their medical charts and screening for first-trimester pregnant mothers.Infection with HIV and subsequent treatment with antiretroviral therapy and seropositivity for hepatitis B and C are associated with metabolic changes and affect the validity of the results.Excluding participants with hepatitis B and C from this study is essential to avoid potential confounding effects on metabolic parameters.These viral infections can induce liver

Data collection procedures
The data were collected using a pre-tested WHO STEPwise Approach to Surveillance (STEPS) for the NCDS, with some modification of the variables.This included information about the participants' sociodemographic status, medical status, lifestyle, and nutritional habits 1 .The questionnaire was first adopted in English and then translated into Amharic by a language expert.It contains sections for assessing demographics, lifestyle behaviors, and medical history records.
Data were collected by appropriately trained midwives and laboratory technologists who were supervised by a principal investigator.Sociodemographic, clinical, and behavioral characteristics and anthropometric data (weight, and height) were collected in the maternity ward (antenatal care clinic) through face-to-face interviews by trained midwifery professionals.In addition, antecubital venous blood specimens were obtained from the pregnant mother by a skilled laboratory technologist in the antenatal care laboratory ward.
Initially, informed consent was obtained, then anthropometric measurements such as blood pressure was taken using medium-sized digital measuring device (BP cuff) after resting for at least five minutes, and the actual pregnant weight was measured for first visit pregnant mothers using balance with weighed to the nearest 0.1 kg in light indoor clothing and bare feet.In addition, another weight for pregnant mothers was obtained during the first antenatal visit by referring to the registration log book.
The actual heights of the participants were measured using a movable stadiometer.Measurements were taken when the subject stood in an erect posture without shoes and recorded to the nearest 0.5 cm and the pre-pregnancy body mass index (BMI) of the mother was calculated using the formula (pre-pregnancy BMI = pre-pregnancy weight for 2nd and 3rd trimesters, and actual weight for 1st trimester divided by actual height squared) 1 .

Diagnosis of MetS
For the diagnosis of MetS, the American Heart Association/National Herat Lung and Blood Institute definition was used.This definition has no absolute requirement for MetS components, population specificity, and a higher prevalence of MetS than other definitions (NCEP ATP III, IDF, and WHO) in pregnant mothers.According to this definition, MetS can be defined as any three or more of the following: elevated waist circumference (according to population-and country-specific definitions), plasma triglycerides ≥ 150 mg/dl or specific treatment for this lipid abnormality, blood pressure of 130/85 mmHg or therapy of previously diagnosed HTN, HDL cholesterol of less than 50 mg/dl, fasting plasma glucose of less than 100 mg/dl, or use of medication to treat increased glucose levels [2][3][4] .

Laboratory procedures and processing
Pre-analytical test Aseptically, five milliliters of venous blood were drawn from the antecubital fossa of the forearm following an overnight fast.Trained laboratory professionals skillfully collected the blood samples.The specimens were placed in serum separator test tubes and allowed to clot at room temperature for 10-20 min.Subsequently, the samples were transported to the laboratory for further analysis.To isolate the serum, the blood samples underwent centrifugation at 3000 rpm for five minutes.The lipid profile tests (Triglycerides, Total Cholesterol, HDL Cholesterol, LDL Cholesterol), along with fasting blood glucose levels, were examined utilizing a Beckman Coulter DXC 700 AU clinical chemistry analyzer.

Analytical test
The lipid profile tests and FBS test were measured at the University of Gondar Comprehensive Specialized Hospital in clinical chemistry laboratory section.After shipment and centrifugation, the samples were analyzed immediately after collection.However, when a delay was expected, the sample was stored in a refrigerator until analysis.The analysis of blood glucose was performed using two enzymes (hexokinase and glucose-6-phosphate dehydrogenase) and NAD+, which are reduced and absorb light at 340 nm measured photometrically.Lipid profiles were measured by sequential enzymatic reactions, and chromophores were added to measure the absorbance.Accelerators or precipitating agents used in the measurement of HDL and LDL in addition to chromophores and the absorbance of lipid profiles (total cholesterol, TAG, HDL, and LD) were measured photometrically at a specific wavelength.In addition, two levels (normal and pathological) of internal quality control (IQC) samples were run before serum samples were run using a Beckman Coulter DXC 700 AU machine.The control sample results were within the acceptable range for running the testing sample.

Quality control measures for data
Before the actual data collection, the quality of the data was assured using a pre-tested questionnaire, which was completed at Maraki Health Center using 5% of the study participants.Data collectors were trained in data collection procedures, and awareness was given which included the relevance of the study, the objective of the study, confidentiality of the information, informed consent, and interview techniques.
The principal investigator reviewed the completed questionnaires at the end of the data collection for completeness.Corrective measures were taken in case of data collection difficulties, accordingly.Moreover, the data was carefully entered, cleaned, and checked for completeness, and missing values were treated accordingly.
The quality of laboratory result was maintained through proper sample collection, transportation, processing and storage and the laboratory analysis were performed by following manufactures instruction.The quality of analytical procedures of laboratory test was maintained by running normal and pathological quality control material before proceeding to run the test sample and the results of quality control material was interpreted based on WESTGARD rules.
Overall, ensuring the accuracy of blood pressure, weight, and height measurements had been pivotal in the reliability of a MetS study.For blood pressure measurements, regular calibration of devices and the use of proper cuff sizes were conducted.Participants were in a rested state, and multiple readings were averaged to ensure consistency.Weight measurements were done from calibrated scales.Participant consistency in clothing, and the removal of heavy items from pockets and footwear were employed.Height measurements employed by calibrated stadiometer, correct participant alignment, and attention to participant comfort.Staff involved in measurements underwent thorough training, and interobserver agreement checked consistently.Regular audits of procedures, equipment, and transparent reporting contributed to the overall quality control of measurements, and standardized protocols were followed consistently.

Data processing and analysis
The pre-pregnant BMI, blood glucose, lipid profile, and blood pressure of pregnant women's results were recoded.The data was entered using Epi-data version 3.1.The data were cleared, edited, and checked for completeness, and then exported to SPSS version 20 for analysis.While organizing and cleaning the data, frequencies and percentages of the participants were calculated.The Pearson chi-square assumption was assessed for categorical variables.s.Univariate and multivariable binary logistic regression was used to measure the association between dependent and independent variables.In the present study, the process of selecting variables for logistic regression comprised a dual-step approach, integrating both univariate and multivariable methods.In the initial phase, univariate analysis was employed to explore individual predictor variables through the use of univariate logistic regression.Subsequently, significance testing was applied to evaluate the statistical significance of each variable's relationship with the outcome.Variables surpassing the significance threshold (P-value < 0.2) were then advanced to the next stage.The subsequent multivariable analysis involved constructing a model using the "enter" method, wherein the selected variables were introduced simultaneously.The significance of each variable within the multivariable model was rigorously assessed.The Hosmer-Lemeshow goodness of fit test with a p-value > 0.05 significant level was used to check the model fitness assumption.The level of statistical significance was set at a 95% confidence interval with a p-value of less than 0.05.Results were presented in the forms of tables, graphs, and narrative illustration.

Ethical consideration
The study was conducted after ethical approval was obtained from the Research and Ethical Review Committee of the School of Biomedical and Laboratory Sciences, University of Gondar (Ref.No/SBMLS/208).The University of Gondar Comprehensive Specialized Hospital granted official permission, and consent was acquired from every study participant prior to commencing the actual data collection.Participants were informed about the risks and benefits of the study; their right to withdraw at any time, confidentiality was maintained using codes.All methods were implemented in accordance with University of Gondar ethical guidelines and regulations.Finally, abnormal findings were linked to the ANC clinic for further evaluation for better management and treatment.The patients/participants provided their consent to participate in this study.For those illiterate participants, the necessary explanation has been made and informed consent has been obtained from a parent and/or legal guardian for study participation.

Socio-demographic characteristics of study participants
A total of 318 study participants with 100% response rate were included in this study.Of these, majority of the participants were found to be aged 20-34, 245 (77%) with a mean age of 28.6 ± 5.4.Most of the participants 272 (85.54%) live in urban areas (Table 1).

Clinical characteristics of study participants
Among the study participants, 310 (97.48%) were non-smokers, 192 (60.38%) of the participants had taken alcohol before and during pregnancy, 294 (92.5%) of study participants did not have regular exercise, 215 (67.6%) with normal sleep duration and 225 (71.21%) utilize standard dietary salt (Table 2).

Prevalence of MetS among pregnant women
American Heart Association /National Heart Lung and Blood Institute of MetS diagnostic criteria was used in this study.Based on this definition, the prevalence of MetS was showed 42 (13.2%)(95% CI: (9.7, 17.0)).Based on trimester of pregnancy, the prevalence of MetS was 10 (3.14%), 15 (4.72%) and 17 (5.35%) in the first, second and third trimester, respectively.This accounts for 23.81%, 35.71%, and 40.48% of the overall MetS among pregnant women, respectively (Fig. 1).

Determinant factors of MetS among pregnant women
Alcohol intake before pregnancy and during pregnancy (p = 0.002), cigarette smoking (p = 0.057), eating noncooked foods at home (p = 0.005), types of oil used at home(p = 0.016), excessive daily salt consumption (p ≤ ), p = < 0.001] were statistically significant with MetS among pregnant women as seen in (Table 3).

Discussion
According to the American Heart Association/ National Heart Lung and Blood Institute (AHA/NHLBI) definition, the overall prevalence of MetS in the present study was 13.2% (95% CI (9.7-17.0)).This study aligns with the reported prevalence in Angola (12.6%) 5 , India (12%) 6 , and a multi-center study conducted in New Zealand, Australia and UK (12.4% and 12.3%) 7,8 .However, the prevalence observed in the current study is than that reported in studies conducted in Cameroon (7%) 9 , Brazil (3%) 10 , India (8%) 11 , and Sri Lanka (5.6%, 5.4%, 4.2%, and 3% based on AHA/NHLBI, IDF, NCEP-ATP III, and WHO diagnosis criteria, respectively) 12 .In contrast, the prevalence observed in the current study was also lower than that reported in studies conducted in Angolan (36% and 29.2% (based on Joint interim analysis and NCEP ATPIII) 5 , Cameroon (17.88%) 13 and a multicenter study in Australia, New Zeeland, and UK (20%) 14 .The variations in the results may stem from differences in gestational age, with some studies focusing on specific pregnancy trimesters.For instance, the study in Brazil, India, and the multicenter study in Australia, New Zealand, and the UK specifically included second-trimester pregnant women 7,8,10,11,14 , and first trimester pregnant women were used in in Sri Lanka 12 .Indeed, the difference in the use of different MetS diagnostic criteria, the sample size and laboratory diagnostic methods used may cause the variation of MetS prevalence.Furthermore, the specific MetS components may account for variations in the prevalence of MetS.For instance, in Angolan pregnant women, the major component of MetS was fasting blood glucose in the joint interim analysis and central obesity in NCEP ATPIII, but high TAG and reduced HDL level was the most frequent MetS components in the current study.Since central obesity and hyperglycemia are the main triggering factors for the pathophysiology of MetS 5 .Insulin resistance and visceral adiposity contribute to dyslipidemia www.nature.com/scientificreports/and endothelial dysfunction, with MetS seemingly necessitating a combination of a metabolic predisposition to insulin resistance and obesity 15 .
The prevalence of TAG in this study was 33.3%.This study was almost similar with the reports in Brazil (31.5%) 10 , a multicenter study in Australia, New Zealand and UK (29.15%) and Angola (28.99%) 5,8 .However, the current study was lower than the findings reported in India (55%, 44%) 6,11 and higher than other studies done in Cameroon (3.7%) 9 , Sri Lanka (6.9%) 12 and a multi-center study in Australia, New Zealand, and UK (24.52%, 25%) 7,14 .The observed discrepancy could be linked to variations in lifestyle factors, ethnicity, genetic influences, and differences in gestational age.
The prevalence of reduced HDL was observed to be 28.6%, showing a similarity to findings in Brazil (31.5%) 10 .The current finding was lower as compared to the studies reported in Cameroon (66%) 13 , India (56%) 11 and Sri Lanka (52.5%) 12 .Conversely, it was higher compared to results in Angola (11.9%) 5 , Cameroon (16.3%) 9 , India www.nature.com/scientificreports/(23%) 6 , and a multi-center study in Australia, New Zealand, and UK) (5.6%, 19.61%, 11.58%) 7,8,14 .The variation may be attributed to differences in gestational age, as HDL concentration tends to decrease with advancing pregnancy 16 .Additionally, genetic, ethnic, and lifestyle factors may contribute to the observed differences in prevalence.The prevalence of elevated DBP/SBP in this study was 18.3%, which was almost consistent report in India (20.5%) 6 .While the current study was lower as compared to the reports in Angola (29.5%) 5 .While a higher prevalence of elevated BP was obtained in the current study as compared to the study done in Sri Lanka (2.3%) 19 , a multi-center study in Australia, New Zealand, and UK (3.69%, 3.65%) (45, 46).The observed difference could be ascribed to variations in ethnicity, genetics, lifestyle factors, and the potential influence of gestational age.Existing evidence suggests that blood pressure (BP) tends to exhibit significant variations as gestational age progresses 16 .
In this study MetS in pregnant mothers was positively associated with alcohol consumption before and during pregnancy (AOR = 4.2, 95% CI (1.6, 10.9), p = 0.003)).This finding was consistent with the findings obtained from the study done in Cameroon, multicenter (Australia, New Zealand, and UK), and other previous studies 8,13,[17][18][19] .Existing evidence suggests that excessive alcohol consumption leads to the accumulation of fat, possibly due to its nutritional content and its impact on suppressing lipid oxidation.Moreover, alcohol is implicated in oxidative stress, which can further influence insulin sensitivity 18,19 .Unhealthy sleep duration (short and long) was also associated with MetS in pregnant women (AOR = 5.6, 95% CI (2.4, 13.1), p = < 0.001) in the present study.This result was consistent with the findings obtained from a particular study done in Cameroon, India and other studies 11,17,[20][21][22] .Scientific data supported that sleep deprivation and circadian disruption are linked to metabolic dysregulation, which may contribute to weight gain, obesity, and type 2 diabetes.Sleep disturbances can potentially trigger MetS by influencing the timing and quantity of food intake, disrupting energy balance, promoting inflammation, and impairing glucose tolerance and insulin sensitivity 23 .Delayed initiation of sleep, particularly after midnight, results in the suppression of the most significant growth hormone pulse and disrupts the secretion of cortisol hormone.Cortisol, often referred to as the "stress hormone," plays a crucial role in the body's response to stress, regulation of metabolism, and maintenance of homeostasis.However, disrupted cortisol secretion is associated with MetS 20 .
In the present study, excessive dietary salt intake was positively associated with the prevalence of MetS (AOR = 4.2, 95% CI (1.8, 9.5), p = 0.001).Health care providers advised that adults should consume no more than 5 g (a little under a teaspoon) of salt per day, according to the WHO in 2015 24 .Consumption of salt beyond the standard leads to kidney work overload, resulting in excess sodium and water retention.A high-salt diet worsens HTN and impairs the response of the vasculature to nitric oxide (NO) and promotes elevated BP 25 .Moreover, changes in metabolic pathways related to sodium sensitivity may bring about obesity and insulin resistance 26 .
As a limitation to this study, assessing MetS in pregnant women using weight and waist circumference has been a challenge.Physiological changes during pregnancy, gestational weight gain, and fluid retention impact the accuracy of these measures.Interpreting waist circumference is challenging due to abdominal expansion.This could lead to non-differential misclassification of MetS.The dynamic nature of metabolic changes is not fully captured, and establishing universal cutoff values is difficult due to population variability.To enhance a better assessment, considering additional biomarkers and accounting for individual variability is crucial for a more comprehensive understanding of metabolic health during pregnancy.
This study highlights a noteworthy prevalence of MetS among pregnant women, accounting 13.21%.High frequency of MetS components were recorded including high TAG levels, low HDL, and elevated blood pressure.Factors contributing to this prevalence include pre-pregnancy conditions, alcohol intake, excessive dietary salt Table 3. Bivariable and multivariable binary logistic regression of MetS with lifestyle, behavioral and clinical factors among pregnant women at the University of Gondar Comprehensive and Specialized Hospital, Gondar, Ethiopia, 2022 (n = 318).AOR adjusted odd ratio, COR crude odd ratio, CI confidence interval, DM diabetes mellitus, HTN hypertension, MetS metabolic syndrome, UOGCSH University of Gondar Comprehensive Specialized Hospital.N.B: * significant at p ≤ 0.05 level, ** highly significant at p < 0.05 level, 1 = the reference group.Other type of oil (soya bean oil, nugget oil, olive oil etc).

Figure 1 .
Figure 1.Proportion of MetS in pregnancy trimester among overall prevalence at the University of Gondar Comprehensive Specialized Hospital, Gondar, Ethiopia, 2022.

Table 2 .
Frequency distribution of lifestyle, behavioral, and clinical factors of pregnant women at the University of Gondar Comprehensive Specialized Hospital, Gondar, Ethiopia, 2022 (n = 318).DM diabetes mellitus, HTN hypertension.